Diabetes is a group of diseases marked by high levels of blood glucose resulting from defects in insulin production, insulin action, or both. There are 23.6 million people in the United States, or 8% of the population, who have diabetes. The total prevalence of diabetes has increased 13.5% since the 2005-2007 time period. Diabetes can lead to serious complications and premature death, but there are well-known products available for people with diabetes to help control the disease and lower the risk of complications. Chronic hyperglycemia leads to serious sometimes irreversible complications including renal failure, peripheral neuropathy, retinopathy, and vascular system complications.
Treatment options for people with diabetes include specialized diets, oral medications and/or insulin therapy. The primary goal for diabetes treatment is to control the patient's blood glucose (sugar) level in order to increase the chances of a complication-free life.
Glycemic control of patients afflicted with Type 1 or Type 2 diabetes mellitus is essential to minimize acute and chronic effects of hypoglycemia or hyperglycemia. Utilization of continuous glucose monitoring (CGM) as a means to measure effectiveness of treatments focuses on attaining glycemic control was first introduced into commercial use over ten years ago. Since that time, CGM's have been incorporated into insulin pumps which automatically infuse insulin when blood sugar levels are measured by the CGM to be above threshold levels chosen by the patient after consultation with their physician.
Glucose sensors are an essential element in diabetes management. In particular, continuous glucose sensors provide numerous advantages over episodic glucose sensors or conventional finger-stick glucose test strips. Artificial pancreas architectures rely on accurate continuous glucose measurements.
Many existing CGM's are presently based on glucose oxidase. More recently, however, Becton, Dickinson and Company has demonstrated a CGM based on a fluorescently labeled glucose binding protein (GBP) contained in a glucose-permeable hydrogel matrix. The glucose binding protein undergoes a conformational change in the presence of glucose, which affects the fluorescence intensity. Accordingly fluorescence emission spectra may be used to determine glucose concentration continuously. One difficulty with fluorescence measuring systems is due to the inherently noisy nature of optical intensity signals. Another problem with CGM devices is with initial calibration, and maintaining calibration over the life of the sensor, to ensure accurate glucose measurements. Accordingly, there is a need for a CGM that is capable of self-calibration and dynamic calibration during use, in order to improve the speed and accuracy of glucose measurements. Although embodiments described herein discuss a GBP contained in a matrix, it should be appreciated that any suitable substance or compound may be contained within the matrix. Embodiments of the present invention are not limited to matrices containing a GBP, and in particular, may include without limitation boronic acid or any glucose binding compound. In addition, it should be understood that embodiments of the present invention may be deployed to any suitable location of a host, including without limitation subcutaneous, intradermal, supradermal, and intravascular space. Further, it should be understood that embodiments of the present invention may be deployed within or utilizing any bodily fluid, including without limitation, blood, urine, interstitial fluid, lymph fluid and tears.